Film-forming apparatus and film-forming method

Abstract

Disclosed is a film-forming method characterized by comprising a step for forming a primary Cu film on a substrate by using a divalent Cu source material, and another step for forming a secondary Cu film on the primary Cu film by using a monovalent Cu source material.

1 . A film forming method comprising:
 forming a primary Cu film on a substrate by using a divalent Cu source material; and   forming a secondary Cu film on the primary Cu film by using a monovalent Cu source material.   
   
   
       2 . A film forming method comprising:
 loading a substrate in a processing vessel;   forming a primary Cu film on the substrate by a chemical vapor deposition (CVD) using a divalent Cu source material; and   forming a secondary Cu film on the primary Cu film by a CVD using a monovalent Cu source material.   
   
   
       3 . The film forming method of  claim 2 , wherein the primary Cu film forming includes:
 (a) supplying the divalent Cu source material onto the substrate to be adsorbed thereon;   (b) stopping the supply of the divalent Cu source material and removing a residual gas from the processing vessel;   (c) supplying a reducing gas onto the substrate and converting the reducing gas into radicals by a plasma, thereby reducing the divalent Cu source material adsorbed on the substrate to form a Cu film on the substrate; and   (d) stopping the supply of the reducing gas and removing a residual gas from the processing vessel.   
   
   
       4 . The film forming method of  claim 2 , wherein the secondary Cu film forming includes supplying the monovalent Cu source material onto the substrate along with a reducing gas. 
   
   
       5 . The film forming method of  claim 3 , wherein the reducing gas is one of H 2 , NH 3 , N 2 H 4 , NH(CH 3 ) 2 , N 2 H 3 CH and N 2  or a gaseous mixture of plural gases selected therefrom. 
   
   
       6 . The film forming method of  claim 2 , wherein a temperature of the substrate in the primary Cu film forming and a temperature of the substrate in the secondary Cu film forming are substantially identical to each other. 
   
   
       7 . The film forming method of  claim 1 , wherein in the primary Cu film forming, the Cu film is formed to have a film thickness ranging from 1 nm to 100 nm. 
   
   
       8 . The film forming method of  claim 1 , wherein the monovalent Cu source material is Cu(hfac)atms or Cu(hfac)TMVS. 
   
   
       9 . The film forming method of  claim 1 , wherein the divalent Cu source material is Cu(dibm) 2 , Cu(hfac) 2 , or Cu(edmdd) 2 . 
   
   
       10 . The film forming method of  claim 1 , wherein the substrate has a barrier film on a surface thereof, the barrier film being made of Ta, TaN, Ti, TiN, W or Wn, and in the primary Cu film forming, the Cu film is formed on the barrier film. 
   
   
       11 . The film forming method of  claim 10 , wherein the barrier film has an adhesive layer on a surface thereof, the adhesive layer being made of Ru, Mg, In, Al, Ag, Co, Nb, B, V, Ir, Pd, Mn, or a Mn oxide (MnO, Mn 3 O 4 , Mn 2 O 3 , MnO 2 , or Mn 2 O 7 ), and in the primary Cu film forming, the Cu film is formed on the adhesive layer. 
   
   
       12 . A film forming apparatus comprising:
 a vacuum evacuable processing vessel for accommodating a substrate therein;   a first Cu source material supply unit for supplying a monovalent Cu source material into the processing vessel in a gas state;   a second Cu source material supply unit for supplying a divalent Cu source material into the processing vessel in a gas state; and   a controller for controlling the first and the second Cu source material supply unit such that a primary Cu film is formed on the substrate in the processing vessel by using the divalent Cu source material and, then, a secondary Cu film is formed on the primary Cu film by using the monovalent Cu source material.   
   
   
       13 . The film forming apparatus of  claim 12 , further comprising:
 a reducing gas supply unit for supplying a reducing gas into the processing vessel; and   a plasma generating unit for converting the supplied reducing gas into a plasma,   wherein the controller controls the first Cu source material supply unit, the second Cu source material supply unit, the reducing gas supply unit and the plasma generating unit such that the primary Cu film is formed by repeating a primary Cu film forming process plural times, the primary Cu film forming process comprising supplying the divalent Cu source material onto the substrate in the processing vessel to be adsorbed thereon; stopping the supply of the divalent Cu source material and evacuating the processing vessel; supplying a reducing gas onto the substrate while converting the reducing gas into radicals by a plasma, thereby reducing the divalent Cu source material adsorbed on the substrate to form the primary Cu film on the substrate; and stopping the supply of the reducing gas and evacuating the processing vessel.   
   
   
       14 . The film forming apparatus of  claim 12 , further comprising a reducing gas supply unit for supplying a reducing gas into the processing vessel,
 wherein the controller controls the first Cu source material supply unit, the second Cu source material supply unit and the reducing gas supply unit such that the secondary Cu film is formed by supplying the monovalent Cu source material onto the substrate in the processing vessel along with the reducing gas.   
   
   
       15 . The film forming apparatus of  claim 12 , further comprising a substrate heating unit for heating the substrate in the processing vessel,
 wherein the controller controls the substrate heating unit such that the formations of the primary Cu film and the secondary Cu film are performed in a state where the substrate is heated up to a specific temperature.   
   
   
       16 . A computer readable storage medium for storing therein a computer executable control program, wherein when executed by a computer for controlling a film forming apparatus for forming a Cu film on a substrate by a CVD method, the control program realizes a control of forming a primary Cu film by using a divalent Cu source material and then forming a secondary Cu film on the primary Cu film by using a monovalent Cu source material. 
   
   
       17 . The computer readable storage medium of  claim 16 , wherein when executed by the computer, the control program realizes a control of repeating the primary Cu film forming process plural times, the primary Cu film forming process comprising supplying the divalent Cu source material onto the substrate in a processing vessel to be adsorbed thereon; stopping the supply of the divalent Cu source material and evacuating the processing vessel; supplying a reducing gas onto the substrate while converting the reducing gas into radicals by a plasma, thereby reducing the divalent Cu source material adsorbed on the substrate to form the Cu film on the substrate; and stopping the supply of the reducing gas and evacuating the processing vessel. 
   
   
       18 . The computer readable storage medium of  claim 16 , wherein when executed by the computer, the control program realizes a control of performing the secondary Cu film forming process of forming the secondary Cu film by supplying the monovalent Cu source material onto the substrate in the processing vessel along with a reducing gas. 
   
   
       19 . The film forming method of  claim 4 , wherein the reducing gas is one of H 2 , NH 3 , N 2 H 4 , NH(CH 3 ) 2 , N 2 H 3 CH and N 2  or a gaseous mixture of plural gases selected therefrom. 
   
   
       20 . The film forming method of  claim 2 , wherein in the primary Cu film forming, the Cu film is formed to have a film thickness ranging from 1 nm to 100 nm. 
   
   
       21 . The film forming method of  claim 2 , wherein the monovalent Cu source material is Cu(hfac)atms or Cu(hfac)TMVS. 
   
   
       22 . The film forming method of  claim 2 , wherein the divalent Cu source material is Cu(dibm) 2 , Cu(hfac) 2 , or Cu(edmdd) 2 . 
   
   
       23 . The film forming method of  claim 2 , wherein the substrate has a barrier film on a surface thereof, the barrier film being made of Ta, TaN, Ti, TiN, W or Wn, and in the primary Cu film forming, the Cu film is formed on the barrier film. 
   
   
       24 . The film forming method of  claim 23 , wherein the barrier film has an adhesive layer on a surface thereof, the adhesive layer being made of Ru, Mg, In, Al, Ag, Co, Nb, B, V, Ir, Pd, Mn, or a Mn oxide (MnO, Mn 3 O 4 , Mn 2 O 3 , MnO 2 , or Mn 2 O 7 ), and in the primary Cu film forming, the Cu film is formed on the adhesive layer.